swapping rear gears......who has done it?? How hard?? Special tools??
#1
swapping rear gears......who has done it?? How hard?? Special tools??
Just what it says. Who has done it. I have a lift and plenty of tools, but not really the know how. My old man has swapped gears before but that was before i was born!!!
Any help would be appreciated!!!! Just wanna know if i'm gonna be over my head. Dealer quoted me 4 hours labor and was pretty clear that they want me to buy the gear set from them.
Any help would be appreciated!!!! Just wanna know if i'm gonna be over my head. Dealer quoted me 4 hours labor and was pretty clear that they want me to buy the gear set from them.
#2
it just depends on how thorough you want to be.
to properly set up the rear axle including replacing all bearings (carrier, pinion, and axle), select fit pinion depth shim, measure and set pinion bearing pre load by hand not impact gun, check backlash and adjust if necessary it could easily take 5 hours to properly set up an 8.8 or 9.75 axle and it requires a few special tools.
BUT most folks just slap a ring gear on the differential, reuse the old pinion depth shim on the new pinion gear MAYBE replacing the large or rear pinion bearing and sometimes only bother to do that if they damaged it during removal from the old gear, hammer the impact nut down with an impact gun and let it eat. some people even reuse the crush sleeve. I have seen this technique done in 45 minutes.
and believe it or not the second technique probably works out just fine about 75% of the time.
it just depends on how you like to do things (read: cheaply or correctly)
good luck.
later,
chris
to properly set up the rear axle including replacing all bearings (carrier, pinion, and axle), select fit pinion depth shim, measure and set pinion bearing pre load by hand not impact gun, check backlash and adjust if necessary it could easily take 5 hours to properly set up an 8.8 or 9.75 axle and it requires a few special tools.
BUT most folks just slap a ring gear on the differential, reuse the old pinion depth shim on the new pinion gear MAYBE replacing the large or rear pinion bearing and sometimes only bother to do that if they damaged it during removal from the old gear, hammer the impact nut down with an impact gun and let it eat. some people even reuse the crush sleeve. I have seen this technique done in 45 minutes.
and believe it or not the second technique probably works out just fine about 75% of the time.
it just depends on how you like to do things (read: cheaply or correctly)
good luck.
later,
chris
#3
#5
at such low mileage I'd leave the axle and carrier bearings alone.
you can reuse the front(small) pinion bearing with no problem. you can reuse the rear(large) pinion bearing IF you have the correct tools OR you are very careful/lucky and can remove it without damaging the cage.
I might have a large pinion bearing on standby just in case.
you should definately get a new crush sleeve or "collapsible spacer" to set the pinion bearing preload, and allthough LOTS of people tighten the pinion nut with an IMPACT gun, this can be VERY hard on the bearings, the crush sleeve should be collapsed by hand with a LARGE breaker bar and maybe even a pipe on the end of that. it'll take A LOT of torque to do this by hand, but it doesn't hammer the bearings like an impact gun will. unfortunately, you also need a DIAL TYPE inch lb torque wrench to measure the pinion bearing "drag" or preload. you have to tighten the nut down, as you tighten it, you'll be collapsing the spacer, this is what puts the "preload" on the bearings. you have to tighten and then measure the drag, you have to sneak up on the correct torque, because if you crush the sleeve too far and put too much preload on the bearings, you'll have to take it apart, install a new sleeve and start all over. another reason not to use an impact gun, it's easy to over torque the nut, it may seem as though it takes forever to reach the proper torque, but once you get there, it's EASY to go too far either by hand or by impact.
IMHO, you should also check and/or select fit the pinion depth shim. but aside from doing a pattern check (which in my opinion is not very exact) I don't know of any way to do this without the Ford special tool kits for axles. I've got the tools to do this one step on an 8.8 axle and I think they cost me well over $300 bucks.
so worst case, you could reuse the existing pinion depth shim (located under the large pinion bearing). and probably be just fine.
good luck.
later,
chris
you can reuse the front(small) pinion bearing with no problem. you can reuse the rear(large) pinion bearing IF you have the correct tools OR you are very careful/lucky and can remove it without damaging the cage.
I might have a large pinion bearing on standby just in case.
you should definately get a new crush sleeve or "collapsible spacer" to set the pinion bearing preload, and allthough LOTS of people tighten the pinion nut with an IMPACT gun, this can be VERY hard on the bearings, the crush sleeve should be collapsed by hand with a LARGE breaker bar and maybe even a pipe on the end of that. it'll take A LOT of torque to do this by hand, but it doesn't hammer the bearings like an impact gun will. unfortunately, you also need a DIAL TYPE inch lb torque wrench to measure the pinion bearing "drag" or preload. you have to tighten the nut down, as you tighten it, you'll be collapsing the spacer, this is what puts the "preload" on the bearings. you have to tighten and then measure the drag, you have to sneak up on the correct torque, because if you crush the sleeve too far and put too much preload on the bearings, you'll have to take it apart, install a new sleeve and start all over. another reason not to use an impact gun, it's easy to over torque the nut, it may seem as though it takes forever to reach the proper torque, but once you get there, it's EASY to go too far either by hand or by impact.
IMHO, you should also check and/or select fit the pinion depth shim. but aside from doing a pattern check (which in my opinion is not very exact) I don't know of any way to do this without the Ford special tool kits for axles. I've got the tools to do this one step on an 8.8 axle and I think they cost me well over $300 bucks.
so worst case, you could reuse the existing pinion depth shim (located under the large pinion bearing). and probably be just fine.
good luck.
later,
chris
#6
also be sure to mark the carrier bearing caps, they are specific left and right, and also they are line bored, so they have to go back on in the same top/bottom orientation as they came off.
also the carrier shims on either side of the carrier bearings need to be kept seperate left and right, they set the backlash, and swapping them will do bad things to your gears. also, DO NOT HIT THESE SHIMS with ANYTHING when trying to reinstall them. they will crack if you even look at them while holding a hammer.
good luck.
later,
chris
also the carrier shims on either side of the carrier bearings need to be kept seperate left and right, they set the backlash, and swapping them will do bad things to your gears. also, DO NOT HIT THESE SHIMS with ANYTHING when trying to reinstall them. they will crack if you even look at them while holding a hammer.
good luck.
later,
chris
#7
Hey Chris
Whats wrong with doing a pattern check?
I take it you mean some machinest blueing and study the wipe marks.
I am also curious what your thoughts are on the backlash? Do you personaly feel going Min, Max, or right in the middle?
I have always felt the tighter the better. I have gotten them as close as .002 with great results.
thx
Greg
Whats wrong with doing a pattern check?
I take it you mean some machinest blueing and study the wipe marks.
I am also curious what your thoughts are on the backlash? Do you personaly feel going Min, Max, or right in the middle?
I have always felt the tighter the better. I have gotten them as close as .002 with great results.
thx
Greg
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#8
the problem on these axles is that by the time you've installed everything properly to do a pattern check, you have already used a collapsible spacer and pressed the large pinion bearing onto the pinion.
due to the design of the axle and location of the actual pinion shim, if your pinion depth is incorrect at this point, you have to dissassemble everything(pressing bearings on/off, crush sleeve, etc) and start over with a new shim and then trial and error again and see if you have it right.
even then, just looking at the pattern is not very precise IMHO.
ford has very specific tools to EXACTLY select the proper shim without much room for error.
eyeballing it with paste leaves room for interpretation and each person may "like" a different setting or depth and again, a change requires basically starting over from scratch.
just my .02
i'm not saying it won't work, and maybe 9 times out of 10 you won't need to change the depth shim, but I like to make sure.
as far as backlash, the carrier side shims determine this, 99% of the time they do not require changing, if they do, then you generally have to special order them in the specific thickness that you need. they are not steel shims and are not included in any kits, you have to figure out which exact thickness you need for each side in order to adjust increase or reduce the backlash and then get those two exact shims from ford. ford calls for up to about .012" backlash, performance applications are often run much tighter, but I've never had any problems running as much as .012 on anything i've done.
later,
chris
due to the design of the axle and location of the actual pinion shim, if your pinion depth is incorrect at this point, you have to dissassemble everything(pressing bearings on/off, crush sleeve, etc) and start over with a new shim and then trial and error again and see if you have it right.
even then, just looking at the pattern is not very precise IMHO.
ford has very specific tools to EXACTLY select the proper shim without much room for error.
eyeballing it with paste leaves room for interpretation and each person may "like" a different setting or depth and again, a change requires basically starting over from scratch.
just my .02
i'm not saying it won't work, and maybe 9 times out of 10 you won't need to change the depth shim, but I like to make sure.
as far as backlash, the carrier side shims determine this, 99% of the time they do not require changing, if they do, then you generally have to special order them in the specific thickness that you need. they are not steel shims and are not included in any kits, you have to figure out which exact thickness you need for each side in order to adjust increase or reduce the backlash and then get those two exact shims from ford. ford calls for up to about .012" backlash, performance applications are often run much tighter, but I've never had any problems running as much as .012 on anything i've done.
later,
chris
Last edited by superfords; 06-08-2004 at 07:49 AM.
#9
Originally posted by superfords
you should definately get a new crush sleeve or "collapsible spacer" to set the pinion bearing preload, and allthough LOTS of people tighten the pinion nut with an IMPACT gun, this can be VERY hard on the bearings,
later,
chris
you should definately get a new crush sleeve or "collapsible spacer" to set the pinion bearing preload, and allthough LOTS of people tighten the pinion nut with an IMPACT gun, this can be VERY hard on the bearings,
later,
chris
BTW...just got your message, will call ya in an hour or so...
#11
due to the design of the axle and location of the actual pinion shim, if your pinion depth is incorrect at this point, you have to dissassemble everything(pressing bearings on/off, crush sleeve, etc) and start over with a new shim and then trial and error again and see if you have it right
#12
I agree with Loosebolt...Hone a inner pinion bearing for easy removal. Set the pinion assembly up using the USED crush sleeve and pinion nut. Yes, the differential has to be installed several times to get the pinion shims, backlash, and pattern correct. Once your calculations are done, you have final assembly with the NEW inner pinion bearing, crush sleeve, and pinion nut.
#13
#14